The papers Organometallics, 10, 1421-1431, 1991; J. Organomet. Chem., 527(1-2), 263-276, 1997; Inorg. Chem., 35(6), 1518-28, 1996; and Inorg. Chem., 34(16), 4092-4105 (English) 1995 report the reaction of bis (iminophosphoranyl) methane (BIPM) which are typically aryl substituted on the phosphorus atom and the nitrogen with group VIII metal halides (chlorides) further comprising at two weakly coordinating ligands (L) such as nitriles or cyclooctadiene, afforded several products depending on the reaction time, type of ligand or nature of the metal. The product could be a N-C chelating type product or a N-N chelating type product. ##STR1##
The products contain alkyl bridges between the phosphinimine groups. Further, none of the references teach or suggest the use of such compounds for the polymerization of alpha olefins.
U.S. Pat. No. 5,557,023 issued September, 1966 teaches the use of some phosphinimines complexes to oligomerize alpha olefins. Rather, the complexes are of the structure indicated below. ##STR2##
wherein R, Q, etc. are as defined in the patent. The structures disclosed in the patent are not the bisphosphinimines of the present invention. While the reference does teach oligomerization, it does not suggest polymerization.
There are a number of patents and papers by Brookhart and/or Gibson disclosing the use of Group 8, 9 or 10 metals to polymerize olefins. However, such papers teach that copolymers are not produced (e.g. WO 98/27124). The present invention proved copolymers of olefins made using a catalyst of a Group 8, 9 or 10 metal other than nickel.
A poster presentation by Christopher M. Ong and Professor D. W. Stephan at the Chemical Institute of Canada's annual meeting in the summer of 1999 discloses phosphinimine complexes of aluminum. One of the complexes disclosed is similar to those of the present invention except that the metal is aluminum rather than a Group 8, 9 or 10 metal other than nickel. As far as Applicants are aware the poster did not disclose the use of such complexes for the polymerization of olefins.
Lecture 60 from the summer ACS meeting discloses a cubic cobalt complex of phosphinimines. The reference does not disclose olefin polymerization using such complexes. The paper "Phosphiniminato-Cluster von Eisen. Die Kristallstrukturen von [FeCl(NPEt.sub.3 ].sub.4, [FeC.vertline.C--SiMe.sub.3)(NPEt.sub.3)].sub.4 and [Fe.sub.3 Cl.sub.4 [NP(NMe.sub.2).sub.3 ].sub.3 ]" also discloses cubic phosphinimine complexes but does not teach their use as olefin polymerization catalysts.